The winter weather in the US last month has been nothing short of crazy, thanks to the encroaching polar vortex. With record low temperatures, snowfall, and power outages, people have been plunged into chaos. Storm Uri brought Texas to a standstill. Is this the new normal the nation can expect from the impact of global warming? What is happening to our winter weather? Here are some answers to these questions.
Is there a historical precedent for storms like these?
This was an unusual cold snap to be sure. ‘Most of the southern states saw their coldest temperatures in decades’ says Sylvia Bennett, a journalist at Academic brits and Next Coursework. While historic to be sure, this was not completely unprecedented. Based on climate data going back many decades; some past cold waves, such as one in 1899, surpassed it in severity. During this cold snap, Tallahassee saw sub-zero temperatures, and New Orleans residents watched ice float down the Mississippi to the frozen Gulf of Mexico!
Are we experiencing more snowfall?
This is a difficult question. The National Weather Service noted that the percent of the continental U.S. covered by snow (nearly three-quarters) is the greatest extent on record, but the record only dates back to 2003. Also, how snow is measured now affects the snowfall totals. ‘Historically, the snow was melted, and snowfall was calculated as 10 times the depth, so an inch of water= 10 inches of snow’ says Dorothy Curtis, a writer at Origin Writings and PhD Kingdom. Christopher Burt, a weather historian, noted though that the average ratio was more like 12:1 or 13:1. Later, people moved to just sticking a ruler vertically in the snow and reading the exact measurement. However, the frequency and where the measurement was taken varied. In the latter half of the 20th century, snowboards, quite literally a wooden board were the new way of measuring. The board was placed outside and the snow on top of the board was measured four times a day. This increased snowfall measurements because it was always being measured at its freshest and fluffiest.
The little research that has been done on snowfall trends generally shows a decline in snowfall since the 1920s. The sharpest areas of decline are in the Pacific Northwest and mid-Atlantic. There are two areas, however, that are seeing an increase in snowfall, the lee side of the Rockies and by the Great Lakes.
It’s also worth noting that people are often surprised that there is substantial snowfall in late January and early February. The truth, however, is that many places in the U.S. see more than half of their annual snowfall totals after January 15th.
Will winter storms increase in severity?
We know, in general, extreme weather will become more commonplace due to global warming. However, attributing winter storms is challenging. The polar vortex is a gigantic circular weather pattern that envelopes the North Pole. The jet stream usually pens this vortex there and keeps the coldest weather there. However, there are times when some of the vortex breaks away, and this when we see wintery weather in places like the U. S., Europe, and Asia. Global warming has been causing chaos with the jet stream and the polar vortex, causing the colder arctic area to shift lower more frequently.
However, there is debate on whether this destabilization will occur more frequently or less frequently over time with the impact of global warming. Some research suggests that jet stream abnormalities will become more frequent as the climate warms, but there are also studies suggesting that the jet stream will stabilize, making those sporadic dips down across the continent less likely.
We do know, however, that colder temperatures will be less likely as the planet warms. Our perception of how we experience temperature may change along with the rising temperatures. What we previously experienced as a warm day now could very well be considered cold in the distant future.
Storm Uri wreaked havoc last month and has left many wondering about how often these storms will happen and why. The answers are somewhat complicated, and data is indicating that global warming is a factor.